content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.basetypes;
  
  import java.util.Objects;
  import java.util.concurrent.atomic.*;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.Flowable;
  import io.reactivex.rxjava3.exceptions.Exceptions;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.internal.subscriptions.SubscriptionHelper;
  
  /**
   * Map the terminal events of a Nono into Publisher and stream its events.
   *
   * @param <T> the value type
   */
  final class NonoFlatMapSignal<T> extends Flowable<T> {
  
      final Nono source;
  
      final Function<? super Throwable, ? extends Publisher<? extends T>> onErrorMapper;
  
      final Supplier<? extends Publisher<? extends T>> onCompleteMapper;
  
      NonoFlatMapSignal(Nono source, Function<? super Throwable, ? extends Publisher<? extends T>> onErrorMapper,
              Supplier<? extends Publisher<? extends T>> onCompleteMapper) {
          this.source = source;
          this.onErrorMapper = onErrorMapper;
          this.onCompleteMapper = onCompleteMapper;
      }
  
      @Override
      protected void subscribeActual(Subscriber<? super T> s) {
          source.subscribe(new FlatMapSignalSubscriber<>(s, onErrorMapper, onCompleteMapper));
      }
  
      static final class FlatMapSignalSubscriber<T> extends AtomicReference<Subscription>
      implements Subscriber<Void>, Subscription {
  
          private static final long serialVersionUID = -1838187298176717779L;
  
          final Subscriber<? super T> downstream;
  
          final Function<? super Throwable, ? extends Publisher<? extends T>> onErrorMapper;
  
          final Supplier<? extends Publisher<? extends T>> onCompleteMapper;
  
          final AtomicLong requested;
  
          Subscription upstream;
  
          FlatMapSignalSubscriber(Subscriber<? super T> downstream,
                  Function<? super Throwable, ? extends Publisher<? extends T>> onErrorMapper,
                          Supplier<? extends Publisher<? extends T>> onCompleteMapper) {
              this.downstream = downstream;
              this.onErrorMapper = onErrorMapper;
              this.onCompleteMapper = onCompleteMapper;
              this.requested = new AtomicLong();
          }
  
          @Override
          public void request(long n) {
              SubscriptionHelper.deferredRequest(this, requested, n);
          }
  
          @Override
          public void cancel() {
              upstream.cancel();
              SubscriptionHelper.cancel(this);
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.validate(this.upstream, s)) {
                  this.upstream = s;
  
                  downstream.onSubscribe(this);
              }
          }
  
          @Override
          public void onNext(Void t) {
              // never called
          }
  
          @Override
          public void onError(Throwable t) {
              Publisher<? extends T> p;
              try {
                  p = Objects.requireNonNull(onErrorMapper.apply(t), "The onErrorMapper returned a null Nono");
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  downstream.onError(ex);
                  return;
              }
  
              p.subscribe(new InnerSubscriber());
          }
  
          @Override
          public void onComplete() {
              Publisher<? extends T> p;
              try {
                  p = Objects.requireNonNull(onCompleteMapper.get(), "The onCompleteMapper returned a null Nono");
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  downstream.onError(ex);
                  return;
              }
  
              p.subscribe(new InnerSubscriber());
          }
  
          void innerSubscribe(Subscription s) {
              SubscriptionHelper.deferredSetOnce(this, requested, s);
          }
  
          final class InnerSubscriber implements Subscriber<T> {
  
              final Subscriber<? super T> a = downstream;
  
              @Override
              public void onSubscribe(Subscription s) {
                  innerSubscribe(s);
              }
  
              @Override
              public void onNext(T t) {
                  a.onNext(t);
              }
  
              @Override
              public void onError(Throwable t) {
                  a.onError(t);
              }
  
              @Override
              public void onComplete() {
                  a.onComplete();
              }
          }
      }
  }
  